Each year there are thousands of chimney fires with the major cause of these dangerous chimney fires being the accumulation of creosote in chimney flues. Airtight stoves are heavy producers of creosote which, in the form of a gas, rises up the chimney and condenses on the flue at the point at which it has cooled to the 255.degree. F. temperature range. Such creosote condensate coats the flue with deposits of different consistencies from liquid to a hard, brittle glaze which do not usually block the flue but result in the flue opening or aperture becoming smaller. In a chimney fire, such hard creosote deposits burn and expand to a light-weight, crusty material two to three times original volume to block the flue partially or totally, or such crusty material is dislodged and falls away from the flue and then lodges and blocks the flue at a lower point.
Brushing is not an answer to this problem as it serves not to remove these hard deposits of creosote but only to expose them by removal of soot and other nonflammable deposits which actually enhances their exposure to heat and oxygen. Thus, many chimney fires have occurred soon after brushing.
Despite long-standing general recognition of this hazard and its source, it was only recently that means operable from a location outside a chimney were provided which enabled effective removal of hard and brittle creosote deposits from the chimney flue. Thus, novel devices of my invention disclosed and claimed in co-pending patent application, Ser. No. 282,968, filed July 13, 1981, now U.S. Pat. No. 4,408,368, serve the purpose and have the additional advantage that they can be used to unblock a chimney while in use or even during a chimney fire. Further, these devices are so designed and constructed that the operator can position himself away from the chimney and out of harm's way as he uses these devices to clear chimneys in use or on fire. In one embodiment of that invention, the creosote deposits are effectively hammered out sufficiently to open the flue passage by repeatedly dropping a weighted cutter assembly down the chimney and raising it up again so that the cutters ram, break and clear away portions of the deposits projecting into the central portion of the flue passageway. In another embodiment, an articulated spring steel pick assembly is carried freely on a cylindrical impacting weight in a manner such that when the cleaning head is repeatedly dropped and raised in the chimney, the deposits are impacted, broken and cleared in generally the manner described above and in addition the articulated steel picks intermittently brush and pick away at and dislodge the deposits as the assembly is caused to rotate in a counter-clockwise manner because of the orientation and form of the articulated spring steel picks.